Overview

The CAN bus is an ISO standard bus originally developed for vehicles. It manages the Chassis Electrical System Control
and is responsible for critical activities like engine electrical, and skid control. This system is also used
to provide vehicle diagnostic information for maintenance. A multi-star configuration seems typical of
this bus with a primary bus line that branches into sub bus lines at its extremities then attaches to
multiple device nodes. Differential voltage is applied over twisted pair at 1.5 to 2.5V and 2.5 to 3.5V
for noise resistant signaling. Bit rates up to 1 Mbit/s are possible at network lengths below 40 m.
Decreasing the bit rate allows longer network distances (e.g., 500 m at 125 kbit/s).
(Jeremiah J. Flerchinger Source)
Controllers supporting CAN FD, an enhanced CAN version with frames up to 64 byte and bit rates up to 4 Mbit/s,
will be available in the second half of 2014. A can4linux version supportig CAN FD on a IFI CAN is ready to be used.

Although developed as car communication network CAN is used in many other areas, industrial, medical, maritime laboratory and more.
Most often with a CAN based higher layer protocol like CANopen on top of it.